Nutrient burn it the most common for burn tips, but the the only reason.
There are a few possible causes for discolored leaf tips, but one of the most common is nutrient burn.
This happens when you are giving cannabis plant too high levels of nutrients. Usually, the first signs of cannabis nutrient burn are yellow or brown tips on leaves after increasing the overall amount of nutrients. As time goes on, the brown continues inward and the tips start curling up. The tips will be dry and easily break off with any pressure.
A potassium deficiency is often mistaken for nutrient burn. One clue is the brown edges go in further that nutrient burn, and doesn’t affect tips as evenly.
Hope that helps and good luck